So, 120 consecutive starts (and finishes) into his Red Bulls career — an ironman record for the MLS — the Red Bulls are the beneficiaries of having the most consistent goalkeeper in the league.

The hook to the Robles story is that, when he was acquired by the Red Bulls through an allocation draft process in 2012, he arrived in a state of psychological ruin after a rough ending with the German club, Karlsruher, for which he played two seasons.

Robles, who grew up in Fort Huachuca, Ariz., as the son of a Puerto Rican father and Korean mother, had been benched by the fourth head coach Karlsruher had in the 2010-11 season. He thought his playing career was all-but over.

“I thought, for the most part, my best days as a soccer player were behind me,’’ Robles told The Post before Saturday night’s Red Bulls home match against Toronto. “The MLS was my last lifeline.’’

And now look where he is. In an April 16 match against Colorado, he set an MLS record for playing 90 minutes in 113 consecutive matches to become the league’s all-time ironman.

That hardly seemed possible on Sept. 29, 2012, the day he started his first match with the Red Bulls.

“I didn’t know what to expect then,’’ Robles said. “I was expecting the unexpected, because of the tumultuous end in Germany and then this random beginning somewhere else. My attitude at the time was … no expectations, no goals.’’

All he has become since is raise expectations and set standards. He has become the rock of the franchise, the glue, most counted-on piece to the starting 11, a team leader in performance on and off the field.

“It’s consistency and professionalism,’’ Red Bulls coach Jesse Marsch said. “He’s been important in so many more ways than just his performances on the field. That’s what I would say has led to why he’s been such a steady presence.’’

Steady is the last way Robles would describe his tumultuous tenure at Karlsruher, a once-proud German club that was battling relegation from the Bundesliga’s second division.

After a first season there (2009-10), when he played 23 matches as the club’s starting keeper, Robles became a scapegoat of the club’s fourth coach in the 2010-11 season and was benched.

“I remember thinking, ‘Maybe I can bounce back from this,’ ” Robles recalled. “But every time I opened the paper, the coach was blasting me.’’

In Robles’ two years with Karlsruher, which he called “a very contentious situation,’’ he said he played for nine head coaches, three general managers and two presidents.

“It’s been four years and it feels like a lifetime ago,’’ Robles said. “Those are the sorts of things that, as a young player, you can never really prepare yourself for — the business side of it.’’

After that 2010-11 season, Robles was released from the German club, but there were roadblocks getting to the Red Bulls, who originally tried to acquire him in January 2012, but he curiously was forced to wait for an allocation draft later on before he could come to MLS.

“They made me jump through hoops and run though walls,’’ he said. “I can’t say this with any evidence, but I felt like [MLS officials] were still a little upset that I left in the first place.’’

Robles was drafted in 2007 by D.C. United but opted to go to Germany for what he thought was a better career opportunity.

In the end, Robles got what he wanted: a chance with the Red Bulls, for which he sounds forever grateful. His payback has been arguably the best player investment the club has made in its 20-plus-year history.

“The biggest quality a guy can have is consistency, and Luis is the epitome of a consistent player — not only on the field but in his overall mindset,’’ Red Bulls backup keeper Ryan Meara said.

Meara was the starter for the Red Bulls in 2012 when they acquired Robles. He was in the conversation for MLS rookie of the year when he suffered a hip injury in July and was out for the rest of the season. After Meara’s replacement, Bill Gaudette, hurt his back, Robles took over. The rest is history.

“Injuries happen,’’ Meara said. “Luis came in, took his opportunity and ran with it.’’

Now, 120 starts later, Robles still is running — with no end in sight.

“If that doesn’t speak to the player and person that he is, I don’t know what does,’’ Red Bulls teammate Connor Lade said of the ironman streak.

“Physically, he’s a beast. He’s the type of guy who, even the day after a game, if they need a second goalie in practice, he’s the one who puts his arm and says, ‘I’ll go in,’ even though he just played 90 minutes the night before,’’ Sacha Kljestan said.

“At 31, this guy can play 10 more years. … Maybe we’ll still be talking when that number is 519 [consecutive] games,’’ Marsch said. “Those tough times he went through prepared him for now.